Diazotype layers containing thiourea derivatives of hydroxy benzene



Patented Dec. 16, 1947 DIAZOTYPE LAYERS CONTAINING THIO- UREADERIVATIVES OF HYDROXY BEN- ZENE William Henry von Glahn, Loudonville,and Lester Nelson Stanley, Delmar, N. Y., assignors to General Aniline &Film Corporation, New York, N. Y., a corporation of Delaware No Drawing.Application December 12, 1945, Serial No. 634,626

8 Claims.

This invention relates to diazotype processes and more particularly tothe use of certain azo components in this art.

With the aid of the new azo components forming an object of thisinvention, very useful lightsensitive materials and prints of very goodquality can be obtained.

In the reproduction of mechanical drawings, printed material, picturesor other originals to be copied, it is of particular advantage to firstmake an intermeditae print or transition print on a transparentdiazotype copying material by juxtapositioning the original to bereproduced to the transparent diazotype material and exposing to actinicrays by either printing through or by the reflex process and thendeveloping the diazotype material, The image produced on the thusobtained intermediate or transition diazotype print can then be used forthe reproduction of further prints. The efliciency of such transitionprints depends upon the opacity of the azo dye image to ultravioletlight and the transparency of the background. When the transparentdiazotype intermediate material contains azo dye components, such asphloroglucin, the diazotype layer has poor stability against precouplingprior to e rposure. A print of a deep color having good visual densitycan be obtained from such a diazotype, but its actinic opacity orphotographic density is not suiiicient to reproduce satisfactorilysubsequent diazo-type copies. The azo dye component must be such as toproduce by coupling with the undecomposed diazo compound a yellow tobrown azo dye which will sufficiently absorb ultraviolet light toprevent light decomposition of the diazo compound in the areas to bereproduced from the intermediate or transition copy.

Azo components such as reso-rcinol have heretofore been employed indiazo-type transition print media for the production of color imageshaving the proper light absorption characteristics for transitionprinting. While the resorcinol and the like components produce the imagein azo dye colors having good opacity to ultraviolet light, theprecoupling stability of the diazotype layer is not sufficient to assureprolonged storage before use. It has been found that transparent paperor film carrying the usual diazo compounds and resorcinol in thelight-sensitive layer for this; purpose gradually develop adiscoloration prior to use, produced by premature coupling andv henceupon subsequent use the background areas will contain thisdiscoloration, thus impairing the ability of these areas to transmitactinic light. Therefore, it is not possible to obtain a colorless;

background in subsequent reproductions obtained from the use of thetransition print as an original and as a consequence such reproductionsdo not exhibit full density of the image and are not clear.

It has now been found that a new class of azo coupling components, notheretofore used in diazotype reproduction media, may be employed in alight-sensitive layer with suitable diazo compounds on a transparentizedpaper or film or other transparent carrier which will give a sepia imageof high actinic opacity and at the same time provide a two-componentdiazotype lightsensitive layer of high stability to precoupling. Thisclass of coupling components includes the 2-, 3-, and l-thioureaderivatives of hydroxy benzene compounds which may be represented by thefollowing general formula:

The ring may be further substituted by any of the usual substituents forphenolic coupling components, such as alkyl, halogen, SOxH, alkoxy,carbalkoxy and sulfamide groups, provided that at least one positionortho to the phenolic group or the para position to the phenolic groupis left unsubstituted and the thiourea radical may be substituted bysuch usual substituents as alkyl, aryl and aralkyl groups. Members ofthis class of compounds include 3-hydroxy phenyl thiourea, Z-hydroxyphenyl thiourea, and 4-hydroxy phenyl thiourea, and substitutedderivatives of these, as indicated above.

Processes for the production of these thiourea derivatives of hydroXybenzene compounds are described in Beilstein 13, 417; Berichte 32, 2115;Beilstein 13, 478 and Beilstein 13, 37 6.

Although this invention will be particularly described as applied to thetwo-component diazotype reproduction method which is the preferredembodiment, it is understood that it can as well be applied to theone-component process or moist developing process. Accordingly,acceptable transition prints can be made by developing an exposeddiazotype layer on a transparent medium containing the diazo compound asthe only dye component with an alkaline developing solution containingthe hydroxy phenyl thiourea, coupling component of this process.

In the preparation of diazotype two-component layers for the,preparation of intermediate or transition prints in accordance with thisinwith such other materials as are ordinarily usedin the preparation ofdiazotype two-component.

light-sensitive coating compositions. As diazo compounds, those derivedfrom p-diamines of the benzene series, particularly those in which oneof the amino groups is substituted by such groups as alkyl, alkoxyalkyl,aryl, aralkyl, alkylol, cycloaliphatic, and heterocyclic groups arepreferred, although others have been found suitable. Examples of suchamines are N-hydroxyethyl-N- methylamino p-amino benzene, p-aminodiphenylamine, l-monoethylamino-Z-(or 3-)methyllamino benzene,1-N-hydroxyethyl-N-ethy1amino- 3.-methyl-4-amino benzene,l.-diethylarnino-3- ethoxy-4.-amino benzene,i-amino-l-benzoylamino-2;5.-diethoxy benzene, p-amino-N-diethylaniline,1-N,N-di(hydroxyethyl)amino-3-chloro-4- amino benzene,p-amino-N-ethyl-N-benzylz.niline, p-amino-N-dimethylaniline,l-ethylamino- 4-aminobenzene, l-hydroxy ethyl-=ethylamino-4- aminobenzene, p-phenylene diamine, i-amino- N,N dioxyalkylaniline and4-ethoxyphenyl-2.5- diethoxyaniline. The diazo compounds are used in theform of their stabilized salts, such as the ZnCl2, CdClz or SnCh doublesalts, fiuorborates, aryl or alkyl sulfonates and acid sulfates of thediazonium compound.

The following examples will serve to. illustrate this invention, butthey arenot intended to limit it thereto.

Example 1 Transparentized paper is coated with a coating solutioncontaining the following materials per 100 cc. of water having anisopropanol content of Grams 3-hydroxy phenyl thiourea 3.8N-hydroxyethyl N'- methylamino p-benzene diazonium chloride-ZnClz doublesalt 3.3

Citric acid 8.0

Thiourea 4.0

The coated transparency. has excellent precoupling" stability and whenexposed to ultraviolet light under a positive original and developedWith gaseous. ammonia givesa sepia dye positive reproduction of. theoriginal on a clear background. Thisisepia: dye reproduction onthetransparentized paper has very good opacity to ultraviolet lightxunder.the sepia dye image, areas and upon subsequent exposure and developmentof an ordinary diazotype reproduction media using the sepia dyeimage'positive as an original, it producesexcellent reproductions in anydesired color.

Example 2' Transparentized paper is coated with a coating solutioncontaining the following materials per 100 cc. of Wa-ter having anisopropanol content of 10%:

Grams 31-hyd1oxy phenyl. thiourea; 3.8 1 ('N -hydroxyethyl N ethyl)amino 3 methyl 4 benzene diazoniurn' chloride- ZnClz double salt 3.5

Citricwacid 8.0 Thiourea. r V h 4.0

The coated transparency has excellent precoupling stability and whenexposed to ultraviolet light under a positive original and developedwith gaseous ammonia gives a sepia dye positive reproduction of theoriginal on a clear background. This sepia dye reproduction on thetransparentized paper has very good opacity to ultraviolet light underthe sepia dye image areas and upon subsequent exposure and developmentof an ordinary diazotype reproduction media using the sepia dye imagepositive as an original, it prodiices excellent reproductions in anydesired color.

Example 3 Transparentizedpaper is coated with a coating solutioncontaining the following materials per cc. of water having anisopropanol content of10%:

Grams 8-hydroxy phenyl thiourea 3.8 2,5,4=-triethoxy diphenyl 4diazonium acid sulfate 3.1

Citric acid 8.0

Thiourea 4.0

The coated transparency has excellent precoupling stability and whenexposed to ultraviolet light under a positive. original and developedwith gaseous ammonia gives a sepia dye positive reproduction of theoriginal on a clear background. This sepia dye reproduction on thetransparentized paper has very. good opacity to ultraviolet light underthe sepia dye image areas and upon subsequent exposure and developmentof an ordinary diazotype. reproduction media using the sepia dye imagepositive as an original, it produces excellent reproductions in anydesired color.

Example 4 Transparentized paper is coated with a coating solutioncontaining the following materials per 100 cc. of water having anisopropanol content of 10%:

Grams 3'-hydroxy phenyl thiourea 3.8 l benzoylamino 2,5 diethoxy 4benzene diazonium chloride-ZnClz double salt 3.5

Citric acid 8.0

Thiourea 4.0

The coated transparency has excellent precoupling stability and whenexposed to ultraviolet light under a positive original and developedwith gaseous ammonia gives a sepia dye positive reproduction of theoriginal on a clear background. This sepia dye reproduction on thetransparentized paper has very good opacity to ultraviolet light underthe sepia dye image areas and upon subsequent exposure anddevelopment'of an ordinary diazotype reproduction media using the sepiadye image positive as an original, it produces excellent reproductionsinany desired. color.

Example 5 Transparentized paper is coated with a coating solutioncontaining the following materials per 1.00 cc. of water having anisopropanol content of 10%:

Grams 3"-hydroxy"phenyl thiourea 2.1 N-diethylamino-p-benzene diazoniumchloride-ZnClz double salt 4.4

Citric acid 8.0

Thiourea 4.0

The coated transparency has excellent precoupling stability and whenexposed to ultraviolet light under a positive original and developedwith gaseous ammonia gives a sepia dye positive reproduction of theoriginal on a clear background. This sepia dye reproduction on thetransparentized paper has very good opacity to ultraviolet light underthe sepia dye image areas and upon subsequent exposure and developmentof an ordinary diazotype reproduction media using the sepia dye imagepositive as an original, it produces excellent reproductions in anydesired color.

Example 6 Transparentized paper is coated with a coating solutioncontaining the following materials per 100 cc. of water having anisopropanol content of Grams Z-hydroxy phenyl thiourea 3.8 p-Phenylaminobenzene diazonium acid sulfate 3.2

Citric acid 8.0

Thiourea 4.0

Example 7 Transparentized paper is coated with a coating solutioncontaining the following materials per 100 cc. of water having anisopropanol content of 10%:

Grams 4-hydroxy phenyl thiourea 3.8 1-ethylarnino-3-methyl-4-benzenediazonium chloride-ZnClz double salt 3.1

Citric acid 8.0

Thiourea 4.0

The coated transparency has excellent preconpling stability and whenexposed to ultraviolet light under a positive original and developedwith gaseous ammonia gives a sepia dye positive reproduction of theoriginal on a clear background.

6 This sepia dye reproduction on the transparentized paper has very goodopacity to ultraviolet light under the sepia dye image areas and uponsubsequent exposure and development of an ordinary diazotypereproduction media using the sepia dye image positive as an original, itproduces excellent reproductions in any desired color.

We claim:

1. As new products, light-sensitive layers on a suitable base containinga suitable light-sensitive diazo compound and an azo coupling componentselected from the class consisting of 2-,

and 4-hydroxy phenyl thiourea compounds unsubstituted at at least one ofthe positions ortho and para to the hydroxy group.

2. As new products, light-sensitive layers on a suitable base comprisinga diazo compound derived from a p-diamino compound of the benzene seriesand an azo coupling component of the class consisting of compoundshaving the formula:

NHfIJNH: S

3. As a new product, light-sensitive layer on a suitable base comprisinga diazo derivative of a p-diamino compound of the benzene series andZ-hydroxy phenyl thiourea.

4. As a new product, a light-sensitive layer on a suitable basecomprising a diazo derivative of a p-diamino compound of the benzeneseries and 3- hydroxy phenyl thiourea.

5. As a new product, a light-sensitive layer on a suitable basecomprising a diazo derivative of a p-diamino compound of the benzeneseries and 4-hydroxy phenyl thiourea.

6. As a new product, a light-sensitive layer on a suitable basecomprising the stabilized salt complex ofN-hydroxyethyl-N-methylamino-p-benzene diazonium chloride and 3-hydroxyphenyl thiourea.

'7. As a new product, a light sensitive layer on a suitable basecomprising p-phenylaminobenzene diazonium acid sulfate and 2-hydroxyphenyl thiourea.

8. As a new product, a light sensitive layer on a suitable basecomprising the stabilized salt complex of l-ethylamino-3-methyl-4-benzene diazonium chloride and 4-hydroxy phenylthiourea.

WILLIAM HENRY VON GLAHN. LESTER NELSON STANLEY.

